The present invention is related to a highly absorbent nonwoven fabric and a process for producing the same. More particularly, the invention is related to a nonwoven fabric that has a high capacity for absorbing polar and nonpolar liquids.
Domestic and industrial wipers are used to quickly pick up both polar liquids, e.g., water and alcohols, and nonpolar liquids, e.g., oil, and these wipers should have a sufficient capacity to hold the absorbed liquid within the wiper structure until it is desired to remove the liquid by pressure such as wringing. Additional necessary properties for wipers are high physical strength and abrasion resistance in that wipers must be able to withstand the tearing, stretching and abrading forces applied during use and should be relatively lint free.
Nonwoven fabrics, especially meltblown nonwoven webs, have been widely used as wipers, especially as disposable wipers. Meltblown nonwoven webs, containing microfibers, have an interfiber capillary structure that is highly suitable for absorbing and retaining liquid. However, meltblown nonwoven webs may not have sufficiently high physical properties, e.g., tear strength and abrasion resistance, that are needed for heavy duty wiper applications and tend to produce lint. Consequently, meltblown nonwoven webs are typically laminated to a support layer, e.g., a spunbond nonwoven fabric, for heavy duty uses and may not make appropriate wipers for uses on abrasive or rough surfaces.
Spunbond and staple fiber nonwoven webs, which contain thicker and stronger fibers than the microfibers of meltblown nonwoven webs and typically are point bonded with heat and pressure, provide desirable strength properties, including tear strength and abrasion resistance. However, spunbond and staple fiber nonwoven webs, which contain relatively thick fibers do not tend to provide fine interfiber capillary structures and thus are less suitable for handling liquid. Furthermore, spunbond and staple fiber nonwoven webs contain bond points that do not have any interfiber structure altogether and form barriers to the flow or transfer of liquid within the nonwoven webs. Spunbond and staple fiber nonwoven webs have not been used widely in wiper applications.
There remains a need for a high strength nonwoven web that exhibits improved absorbent properties along with desirable strength properties.